Comet Holmes in Outburst (APOD 26 Oct 2007)

craterchains · Post by **craterchains** » Sat Nov 03, 2007 11:04 am

That something "dusted" it off? 8)

Chris Peterson · Post by **Chris Peterson** » Sat Nov 03, 2007 2:33 pm

JohnD wrote:Many comets have two tails, one dust, the other plasma (?- electrically charged, anyway) that curves. If we can't see that curving tail, then Holmes doesn't have one. What does this tell us about Holmes?

Both a dust tail and ion tail are starting to show up in images. Presumably, the comet's distance from the Sun slowed their formation, and the very large and fast growing coma hid them from us until they grew long enough to finally become visible around the comet's edge.

orin stepanek · Post by **orin stepanek** » Sat Nov 03, 2007 4:09 pm

This comet is interesting in several ways: We can't see the tail; It flared up suddenly: and it resides in the asteroid belt. Makes you wonder if there is a strong similarity between comets and asteroids. Maybe comets have more ice because: generally, they reside so far away and haven't had the solar encounters devoid them of their water content yet!

Orin

ta152h0 · Post by **ta152h0** » Sat Nov 03, 2007 7:55 pm

Doesn't take much of a collision to produce large clouds of material. Remember what a little bitty piece of copper did to tempel 1 ? I remember well the oooohhs and ahhhhhhs and awmygods...........I have read many comments that the chances of getting hit are very small and the jury is still out on what happened. Maybe a UFO gas tank blew up............................naw, sorry guys. back to serious stuff, pass the beer

NoelC · Post by **NoelC** » Mon Nov 05, 2007 3:48 am

It has a plasma tail. A number of amateurs have imaged it, including myself and my friend.

An amateur astroimager in the UK has captured a closeup of the head with a curving dark line, which looks for all the world like obscuring dust, across it. This could be a clue to what happened to cause it to brighten.

http://ukastroimaging.co.uk/forums/inde ... ic=33279.0

-Noel

orin stepanek · Post by **orin stepanek** » Mon Nov 05, 2007 1:29 pm

The tail has come!

http://antwrp.gsfc.nasa.gov/apod/ap071105.html; Yah!
Orin

ta152h0 · Post by **ta152h0** » Mon Nov 05, 2007 5:55 pm

yahoooooooo the tail has a comet attached. I just found the pictorial of the orbit and it is way above the ecliptic. Assuming a lot of dust in the ecliptic plane, does that imply increased sunlight above ( or below ) the ecliptic ? It seems like this comet is reacting quite strongly despite the great distance from the sun.

Chris Peterson · Post by **Chris Peterson** » Mon Nov 05, 2007 6:06 pm

ta152h0 wrote:yahoooooooo the tail has a comet attached. I just found the pictorial of the orbit and it is way above the ecliptic. Assuming a lot of dust in the ecliptic plane, does that imply increased sunlight above ( or below ) the ecliptic ? It seems like this comet is reacting quite strongly despite the great distance from the sun.

No, the amount of solar energy lost to dust absorption in the ecliptic plane is really tiny. Comets outside the orbit of Mars can produce dust trails, as long at the comet is active enough to be producing dust, as Holmes is. It probably had a tail within hours of its outburst, but it took a week before it stretched out enough to finally show since it's almost directly behind the comet.

ta152h0 · Post by **ta152h0** » Mon Nov 05, 2007 6:15 pm

Is it not the case that the only mechanisms for cometary activity is sunlight light pressure and heat, collisions and close encounters with planets ?

Chris Peterson · Post by **Chris Peterson** » Mon Nov 05, 2007 6:32 pm

ta152h0 wrote:Is it not the case that the only mechanisms for cometary activity is sunlight light pressure and heat, collisions and close encounters with planets ?

Depends what you mean by "activity". Certainly, all those things can influence the appearance of a comet. But by far the dominant mechanism for what is usually called activity is heat. First you need to boil off gas, which carries dust with it. Then the solar wind can sweep it away, producing the characteristic tail. Collisions and close encounters with planets may expose interior surfaces, allowing volatiles to escape easier. But I wouldn't say that of themselves they produce activity.

ta152h0 · Post by **ta152h0** » Tue Nov 06, 2007 7:47 pm

By activity I mean the difference between a rock serenely cruising thru space mostly unnoticed and a rock getting pulverised by other rocks while doing so, becoming noticed by us. Becoming noticed by us is the key concept here. Pass the beer

As our " eyes ' get better, this concept of " serenely cruising thru space unnoticed " becomes harder to do.

JohnD · Post by **JohnD** » Tue Nov 06, 2007 10:00 pm

orin stepanek wrote:The tail has come! :P http://antwrp.gsfc.nasa.gov/apod/ap071105.html; Yah!
Orin

YeeeeeeeeeeeeHA!
Am I a prophet or am I a prophet?

John

orin stepanek · Post by **orin stepanek** » Wed Nov 07, 2007 3:44 pm

JohnD wrote:
orin stepanek wrote:The tail has come! http://antwrp.gsfc.nasa.gov/apod/ap071105.html; Yah!
Orin
YeeeeeeeeeeeeHA!
Am I a prophet or am I a prophet?

John

Oh my; now we have God and a Prophet!

Just joking JohnD
Orin

JohnD · Post by **JohnD** » Wed Nov 07, 2007 10:30 pm

And a star rising in the .......................
Actually, I don't know where Comet Holmes rises.

John the Church of England
(if I'm anything, but I'm not a Baptist)

craterchains · Post by **craterchains** » Thu Nov 08, 2007 9:58 am

, , , and upon this "rock" I will build my church.

Sorry, just couldn't help myself.

FieryIce · Post by **FieryIce** » Thu Nov 08, 2007 2:09 pm

... His tail swept down a third of the stars of heaven and threw
them to the earth.....

Ohhh I just couldn't resist.

orin stepanek · Post by **orin stepanek** » Thu Nov 08, 2007 2:11 pm

JohnD wrote:And a star rising in the .......................
Actually, I don't know where Comet Holmes rises.

John the Church of England
(if I'm anything, but I'm not a Baptist)

Probably in the East as does most objects due to rotation of the Earth.
Orin

JohnD · Post by **JohnD** » Thu Nov 08, 2007 6:41 pm

Look, I'm not claimimg anything for myself, but this is getting more and more significant!

JohnD · Post by **JohnD** » Tue Nov 13, 2007 1:22 pm

FieryIce wrote:... His tail swept down a third of the stars of heaven and threw
them to the earth.....

Ohhh I just couldn't resist.

I had to Google that - Revelations 12:1-17
see: http://www.westminsterstpauls.ca/church ... ?SER_ID=72
Or of course consult your Bible.

Fierce stuff!
But a reasonable description of a mighty comet!

John

Starship Asterisk*

Comet Holmes in Outburst (APOD 26 Oct 2007)

comet collision ?

Plasma Tail Exists

tail

Re: tail

cometary activity

Re: cometary activity

by activity i mean